mcs/mcs/attribute.cs

   1 //
   2 // attribute.cs: Attribute Handler
   3 //
   4 // Author: Ravi Pratap (ravi@ximian.com)
   5 //         Marek Safar (marek.safar@seznam.cz)
   6 //
   7 // Dual licensed under the terms of the MIT X11 or GNU GPL
   8 //
   9 // Copyright 2001-2003 Ximian, Inc (http://www.ximian.com)
  10 // Copyright 2003-2008 Novell, Inc.
  11 //
  12
  13 using System;
  14 using System.Diagnostics;
  15 using System.Collections.Generic;
  16 using System.Reflection;
  17 using System.Reflection.Emit;
  18 using System.Runtime.InteropServices;
  19 using System.Runtime.CompilerServices;
  20 using System.Security;
  21 using System.Security.Permissions;
  22 using System.Text;
  23 using System.IO;
  24
  25 namespace Mono.CSharp {
  26
  27         /// <summary>
  28         ///   Base class for objects that can have Attributes applied to them.
  29         /// </summary>
  30         public abstract class Attributable {
  31                 //
  32                 // Holds all attributes attached to this element
  33                 //
  34                 protected Attributes attributes;
  35
  36                 public void AddAttributes (Attributes attrs, IMemberContext context)
  37                 {
  38                         if (attrs == null)
  39                                 return;
  40
  41                         if (attributes == null)
  42                                 attributes = attrs;
  43                         else
  44                                 throw new NotImplementedException ();
  45
  46                         attributes.AttachTo (this, context);
  47                 }
  48
  49                 public Attributes OptAttributes {
  50                         get {
  51                                 return attributes;
  52                         }
  53                         set {
  54                                 attributes = value;
  55                         }
  56                 }
  57
  58                 /// <summary>
  59                 /// Use member-specific procedure to apply attribute @a in @cb to the entity being built in @builder
  60                 /// </summary>
  61                 public abstract void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa);
  62
  63                 /// <summary>
  64                 /// Returns one AttributeTarget for this element.
  65                 /// </summary>
  66                 public abstract AttributeTargets AttributeTargets { get; }
  67
  68                 public abstract bool IsClsComplianceRequired ();
  69
  70                 /// <summary>
  71                 /// Gets list of valid attribute targets for explicit target declaration.
  72                 /// The first array item is default target. Don't break this rule.
  73                 /// </summary>
  74                 public abstract string[] ValidAttributeTargets { get; }
  75         };
  76
  77         public class Attribute : Expression
  78         {
  79                 public readonly string ExplicitTarget;
  80                 public AttributeTargets Target;
  81                 readonly ATypeNameExpression expression;
  82
  83                 Arguments PosArguments;
  84                 Arguments NamedArguments;
  85
  86                 bool resolve_error;
  87                 readonly bool nameEscaped;
  88
  89                 //
  90                 // An attribute can be attached to multiple targets (e.g. multiple fields)
  91                 //
  92                 protected Attributable[] targets;
  93
  94                 //
  95                 // A member context for the attribute, it's much easier to hold it here
  96                 // than trying to pull it during resolve
  97                 //
  98                 IMemberContext context;
  99
 100                 static readonly AttributeUsageAttribute DefaultUsageAttribute = new AttributeUsageAttribute (AttributeTargets.All);
 101                 static Assembly orig_sec_assembly;
 102                 public static readonly object[] EmptyObject = new object [0];
 103
 104                 // non-null if named args present after Resolve () is called
 105                 PropertyInfo [] prop_info_arr;
 106                 FieldInfo [] field_info_arr;
 107                 object [] field_values_arr;
 108                 object [] prop_values_arr;
 109                 object [] pos_values;
 110
 111                 static Dictionary<Type, AttributeUsageAttribute> usage_attr_cache;
 112                 // Cache for parameter-less attributes
 113                 static Dictionary<Type, CustomAttributeBuilder> att_cache;
 114
 115                 public Attribute (string target, ATypeNameExpression expr, Arguments[] args, Location loc, bool nameEscaped)
 116                 {
 117                         this.expression = expr;
 118                         if (args != null) {
 119                                 PosArguments = args [0];
 120                                 NamedArguments = args [1];
 121                         }
 122                         this.loc = loc;
 123                         ExplicitTarget = target;
 124                         this.nameEscaped = nameEscaped;
 125                 }
 126
 127                 public Attribute Clone ()
 128                 {
 129                         Attribute a = new Attribute (ExplicitTarget, expression, null, loc, nameEscaped);
 130                         a.PosArguments = PosArguments;
 131                         a.NamedArguments = NamedArguments;
 132                         return a;
 133                 }
 134
 135                 static Attribute ()
 136                 {
 137                         Reset ();
 138                 }
 139
 140                 public static void Reset ()
 141                 {
 142                         usage_attr_cache = new Dictionary<Type, AttributeUsageAttribute> (ReferenceEquality<Type>.Default);
 143                         att_cache = new Dictionary<Type, CustomAttributeBuilder> (ReferenceEquality<Type>.Default);
 144                 }
 145
 146                 //
 147                 // When the same attribute is attached to multiple fiels
 148                 // we use @target field as a list of targets. The attribute
 149                 // has to be resolved only once but emitted for each target.
 150                 //
 151                 public virtual void AttachTo (Attributable target, IMemberContext context)
 152                 {
 153                         if (this.targets == null) {
 154                                 this.targets = new Attributable[] { target };
 155                                 this.context = context;
 156                                 return;
 157                         }
 158
 159                         // Resize target array
 160                         Attributable[] new_array = new Attributable [this.targets.Length + 1];
 161                         targets.CopyTo (new_array, 0);
 162                         new_array [targets.Length] = target;
 163                         this.targets = new_array;
 164
 165                         // No need to update context, different targets cannot have
 166                         // different contexts, it's enough to remove same attributes
 167                         // from secondary members.
 168
 169                         target.OptAttributes = null;
 170                 }
 171
 172                 static void Error_InvalidNamedArgument (ResolveContext rc, NamedArgument name)
 173                 {
 174                         rc.Report.Error (617, name.Location, "`{0}' is not a valid named attribute argument. Named attribute arguments " +
 175                                       "must be fields which are not readonly, static, const or read-write properties which are " +
 176                                       "public and not static",
 177                               name.Name);
 178                 }
 179
 180                 static void Error_InvalidNamedArgumentType (ResolveContext rc, NamedArgument name)
 181                 {
 182                         rc.Report.Error (655, name.Location,
 183                                 "`{0}' is not a valid named attribute argument because it is not a valid attribute parameter type",
 184                                 name.Name);
 185                 }
 186
 187                 public static void Error_AttributeArgumentNotValid (ResolveContext rc, Location loc)
 188                 {
 189                         rc.Report.Error (182, loc,
 190                                       "An attribute argument must be a constant expression, typeof " +
 191                                       "expression or array creation expression");
 192                 }
 193
 194                 public void Error_MissingGuidAttribute ()
 195                 {
 196                         Report.Error (596, Location, "The Guid attribute must be specified with the ComImport attribute");
 197                 }
 198
 199                 public void Error_MisusedExtensionAttribute ()
 200                 {
 201                         Report.Error (1112, Location, "Do not use `{0}' directly. Use parameter modifier `this' instead", GetSignatureForError ());
 202                 }
 203
 204                 public void Error_MisusedDynamicAttribute ()
 205                 {
 206                         Report.Error (1970, loc, "Do not use `{0}' directly. Use `dynamic' keyword instead", GetSignatureForError ());
 207                 }
 208
 209                 /// <summary>
 210                 /// This is rather hack. We report many emit attribute error with same error to be compatible with
 211                 /// csc. But because csc has to report them this way because error came from ilasm we needn't.
 212                 /// </summary>
 213                 public void Error_AttributeEmitError (string inner)
 214                 {
 215                         Report.Error (647, Location, "Error during emitting `{0}' attribute. The reason is `{1}'",
 216                                       TypeManager.CSharpName (Type), inner);
 217                 }
 218
 219                 public void Error_InvalidSecurityParent ()
 220                 {
 221                         Error_AttributeEmitError ("it is attached to invalid parent");
 222                 }
 223
 224                 Attributable Owner {
 225                         get {
 226                                 return targets [0];
 227                         }
 228                 }
 229
 230                 protected virtual TypeExpr ResolveAsTypeTerminal (Expression expr, IMemberContext ec)
 231                 {
 232                         return expr.ResolveAsTypeTerminal (ec, false);
 233                 }
 234
 235                 Type ResolvePossibleAttributeType (ATypeNameExpression expr, ref bool is_attr)
 236                 {
 237                         TypeExpr te = ResolveAsTypeTerminal (expr, context);
 238                         if (te == null)
 239                                 return null;
 240
 241                         Type t = te.Type;
 242                         if (TypeManager.IsSubclassOf (t, TypeManager.attribute_type)) {
 243                                 is_attr = true;
 244                         } else {
 245                                 Report.SymbolRelatedToPreviousError (t);
 246                                 Report.Error (616, Location, "`{0}': is not an attribute class", TypeManager.CSharpName (t));
 247                         }
 248                         return t;
 249                 }
 250
 251                 /// <summary>
 252                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 253                 /// </summary>
 254                 void ResolveAttributeType ()
 255                 {
 256                         SessionReportPrinter resolve_printer = new SessionReportPrinter ();
 257                         ReportPrinter prev_recorder = context.Compiler.Report.SetPrinter (resolve_printer);
 258
 259                         bool t1_is_attr = false;
 260                         bool t2_is_attr = false;
 261                         Type t1, t2;
 262                         ATypeNameExpression expanded = null;
 263
 264                         try {
 265                                 t1 = ResolvePossibleAttributeType (expression, ref t1_is_attr);
 266
 267                                 if (nameEscaped) {
 268                                         t2 = null;
 269                                 } else {
 270                                         expanded = (ATypeNameExpression) expression.Clone (null);
 271                                         expanded.Name += "Attribute";
 272
 273                                         t2 = ResolvePossibleAttributeType (expanded, ref t2_is_attr);
 274                                 }
 275
 276                                 resolve_printer.EndSession ();
 277                         } finally {
 278                                 context.Compiler.Report.SetPrinter (prev_recorder);
 279                         }
 280
 281                         if (t1_is_attr && t2_is_attr) {
 282                                 Report.Error (1614, Location, "`{0}' is ambiguous between `{1}' and `{2}'. Use either `@{0}' or `{0}Attribute'",
 283                                         GetSignatureForError (), expression.GetSignatureForError (), expanded.GetSignatureForError ());
 284                                 resolve_error = true;
 285                                 return;
 286                         }
 287
 288                         if (t1_is_attr) {
 289                                 Type = t1;
 290                                 return;
 291                         }
 292
 293                         if (t2_is_attr) {
 294                                 Type = t2;
 295                                 return;
 296                         }
 297
 298                         resolve_printer.Merge (prev_recorder);
 299                         resolve_error = true;
 300                 }
 301
 302                 public virtual Type ResolveType ()
 303                 {
 304                         if (Type == null && !resolve_error)
 305                                 ResolveAttributeType ();
 306                         return Type;
 307                 }
 308
 309                 public override string GetSignatureForError ()
 310                 {
 311                         if (Type != null)
 312                                 return TypeManager.CSharpName (Type);
 313
 314                         return expression.GetSignatureForError ();
 315                 }
 316
 317                 public bool HasSecurityAttribute {
 318                         get {
 319                                 PredefinedAttribute pa = PredefinedAttributes.Get.Security;
 320                                 return pa.IsDefined && TypeManager.IsSubclassOf (type, pa.Type);
 321                         }
 322                 }
 323
 324                 public bool IsValidSecurityAttribute ()
 325                 {
 326                         return HasSecurityAttribute && IsSecurityActionValid (false);
 327                 }
 328
 329                 static bool IsValidArgumentType (Type t)
 330                 {
 331                         if (t.IsArray)
 332                                 t = TypeManager.GetElementType (t);
 333
 334                         return t == TypeManager.string_type ||
 335                                 TypeManager.IsPrimitiveType (t) ||
 336                                 TypeManager.IsEnumType (t) ||
 337                                 t == TypeManager.object_type ||
 338                                 t == TypeManager.type_type;
 339                 }
 340
 341                 // TODO: Don't use this ambiguous value
 342                 public string Name {
 343                         get { return expression.Name; }
 344                 }
 345
 346                 void ApplyModuleCharSet (ResolveContext rc)
 347                 {
 348                         if (Type != PredefinedAttributes.Get.DllImport)
 349                                 return;
 350
 351                         if (!RootContext.ToplevelTypes.HasDefaultCharSet)
 352                                 return;
 353
 354                         const string CharSetEnumMember = "CharSet";
 355                         if (NamedArguments == null) {
 356                                 NamedArguments = new Arguments (1);
 357                         } else {
 358                                 foreach (NamedArgument a in NamedArguments) {
 359                                         if (a.Name == CharSetEnumMember)
 360                                                 return;
 361                                 }
 362                         }
 363
 364                         NamedArguments.Add (new NamedArgument (CharSetEnumMember, loc,
 365                                 Constant.CreateConstant (rc, typeof (CharSet), RootContext.ToplevelTypes.DefaultCharSet, Location)));
 366                 }
 367
 368                 public Report Report {
 369                         get { return context.Compiler.Report; }
 370                 }
 371
 372                 public CustomAttributeBuilder Resolve ()
 373                 {
 374                         if (resolve_error)
 375                                 return null;
 376
 377                         resolve_error = true;
 378
 379                         if (Type == null) {
 380                                 ResolveAttributeType ();
 381                                 if (Type == null)
 382                                         return null;
 383                         }
 384
 385                         if (Type.IsAbstract) {
 386                                 Report.Error (653, Location, "Cannot apply attribute class `{0}' because it is abstract", GetSignatureForError ());
 387                                 return null;
 388                         }
 389
 390                         ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (Type);
 391                         if (obsolete_attr != null) {
 392                                 AttributeTester.Report_ObsoleteMessage (obsolete_attr, TypeManager.CSharpName (Type), Location, Report);
 393                         }
 394
 395                         CustomAttributeBuilder cb;
 396                         if (PosArguments == null && NamedArguments == null) {
 397                                 if (att_cache.TryGetValue (Type, out cb)) {
 398                                         resolve_error = false;
 399                                         return cb;
 400                                 }
 401                         }
 402
 403                         ResolveContext rc = new ResolveContext (context, ResolveContext.Options.ConstantScope);
 404                         ConstructorInfo ctor = ResolveConstructor (rc);
 405                         if (ctor == null) {
 406                                 if (Type is TypeBuilder &&
 407                                     TypeManager.LookupDeclSpace (Type).MemberCache == null)
 408                                         // The attribute type has been DefineType'd, but not Defined.  Let's not treat it as an error.
 409                                         // It'll be resolved again when the attached-to entity is emitted.
 410                                         resolve_error = false;
 411                                 return null;
 412                         }
 413
 414                         ApplyModuleCharSet (rc);
 415
 416                         try {
 417                                 // SRE does not allow private ctor but we want to report all source code errors
 418                                 if (ctor.IsPrivate)
 419                                         return null;
 420
 421                                 if (NamedArguments == null) {
 422                                         cb = new CustomAttributeBuilder (ctor, pos_values);
 423
 424                                         if (pos_values.Length == 0)
 425                                                 att_cache.Add (Type, cb);
 426
 427                                         resolve_error = false;
 428                                         return cb;
 429                                 }
 430
 431                                 if (!ResolveNamedArguments (rc)) {
 432                                         return null;
 433                                 }
 434
 435                                 cb = new CustomAttributeBuilder (ctor, pos_values,
 436                                                 prop_info_arr, prop_values_arr,
 437                                                 field_info_arr, field_values_arr);
 438
 439                                 resolve_error = false;
 440                                 return cb;
 441                         }
 442                         catch (Exception) {
 443                                 Error_AttributeArgumentNotValid (rc, Location);
 444                                 return null;
 445                         }
 446                 }
 447
 448                 protected virtual ConstructorInfo ResolveConstructor (ResolveContext ec)
 449                 {
 450                         if (PosArguments != null) {
 451                                 bool dynamic;
 452                                 PosArguments.Resolve (ec, out dynamic);
 453                                 if (dynamic) {
 454                                         Error_AttributeArgumentNotValid (ec, loc);
 455                                         return null;
 456                                 }
 457                         }
 458
 459                         MethodGroupExpr mg = MemberLookupFinal (ec, ec.CurrentType,
 460                                 Type, ConstructorInfo.ConstructorName, MemberTypes.Constructor,
 461                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 462                                 Location) as MethodGroupExpr;
 463
 464                         if (mg == null)
 465                                 throw new NotImplementedException ();
 466
 467                         mg = mg.OverloadResolve (ec, ref PosArguments, false, Location);
 468                         if (mg == null)
 469                                 return null;
 470
 471                         ConstructorInfo constructor = (ConstructorInfo)mg;
 472                         if (PosArguments == null) {
 473                                 pos_values = EmptyObject;
 474                                 return constructor;
 475                         }
 476
 477                         AParametersCollection pd = TypeManager.GetParameterData (constructor);
 478
 479                         if (!PosArguments.GetAttributableValue (ec, out pos_values))
 480                                 return null;
 481
 482                         // Here we do the checks which should be done by corlib or by runtime.
 483                         // However Zoltan doesn't like it and every Mono compiler has to do it again.
 484                         PredefinedAttributes pa = PredefinedAttributes.Get;
 485                         if (Type == pa.Guid) {
 486                                 try {
 487                                         new Guid ((string)pos_values [0]);
 488                                 }
 489                                 catch (Exception e) {
 490                                         Error_AttributeEmitError (e.Message);
 491                                         return null;
 492                                 }
 493                         }
 494
 495                         if (Type == pa.AttributeUsage && (int)pos_values [0] == 0) {
 496                                 ec.Report.Error (591, Location, "Invalid value for argument to `System.AttributeUsage' attribute");
 497                                 return null;
 498                         }
 499
 500                         if (Type == pa.IndexerName || Type == pa.Conditional) {
 501                                 string v = pos_values [0] as string;
 502                                 if (!Tokenizer.IsValidIdentifier (v) || Tokenizer.IsKeyword (v)) {
 503                                         ec.Report.Error (633, PosArguments [0].Expr.Location,
 504                                                 "The argument to the `{0}' attribute must be a valid identifier", GetSignatureForError ());
 505                                         return null;
 506                                 }
 507                         }
 508
 509                         if (Type == pa.MethodImpl && pos_values.Length == 1 &&
 510                                 pd.Types [0] == TypeManager.short_type &&
 511                                 !System.Enum.IsDefined (typeof (MethodImplOptions), pos_values [0].ToString ())) {
 512                                 Error_AttributeEmitError ("Incorrect argument value.");
 513                                 return null;
 514                         }
 515
 516                         return constructor;
 517                 }
 518
 519                 protected virtual bool ResolveNamedArguments (ResolveContext ec)
 520                 {
 521                         int named_arg_count = NamedArguments.Count;
 522
 523                         var field_infos = new List<FieldInfo> (named_arg_count);
 524                         var prop_infos  = new List<PropertyInfo> (named_arg_count);
 525                         var field_values = new List<object> (named_arg_count);
 526                         var prop_values = new List<object> (named_arg_count);
 527
 528                         var seen_names = new List<string> (named_arg_count);
 529
 530                         foreach (NamedArgument a in NamedArguments) {
 531                                 string name = a.Name;
 532                                 if (seen_names.Contains (name)) {
 533                                         ec.Report.Error (643, a.Location, "Duplicate named attribute `{0}' argument", name);
 534                                         continue;
 535                                 }
 536
 537                                 seen_names.Add (name);
 538
 539                                 a.Resolve (ec);
 540
 541                                 Expression member = Expression.MemberLookup (ec.Compiler,
 542                                         ec.CurrentType, Type, name,
 543                                         MemberTypes.All,
 544                                         BindingFlags.Public | BindingFlags.Instance | BindingFlags.Static,
 545                                         Location);
 546
 547                                 if (member == null) {
 548                                         member = Expression.MemberLookup (ec.Compiler, ec.CurrentType, Type, name,
 549                                                 MemberTypes.All, BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static,
 550                                                 Location);
 551
 552                                         if (member != null) {
 553                                                 ec.Report.SymbolRelatedToPreviousError (member.Type);
 554                                                 Expression.ErrorIsInaccesible (Location, member.GetSignatureForError (), ec.Report);
 555                                                 return false;
 556                                         }
 557                                 }
 558
 559                                 if (member == null){
 560                                         Expression.Error_TypeDoesNotContainDefinition (ec, Location, Type, name);
 561                                         return false;
 562                                 }
 563
 564                                 if (!(member is PropertyExpr || member is FieldExpr)) {
 565                                         Error_InvalidNamedArgument (ec, a);
 566                                         return false;
 567                                 }
 568
 569                                 ObsoleteAttribute obsolete_attr;
 570
 571                                 if (member is PropertyExpr) {
 572                                         PropertyInfo pi = ((PropertyExpr) member).PropertyInfo;
 573
 574                                         if (!pi.CanWrite || !pi.CanRead || pi.GetGetMethod ().IsStatic) {
 575                                                 ec.Report.SymbolRelatedToPreviousError (pi);
 576                                                 Error_InvalidNamedArgument (ec, a);
 577                                                 return false;
 578                                         }
 579
 580                                         if (!IsValidArgumentType (member.Type)) {
 581                                                 ec.Report.SymbolRelatedToPreviousError (pi);
 582                                                 Error_InvalidNamedArgumentType (ec, a);
 583                                                 return false;
 584                                         }
 585
 586                                         object value;
 587                                         if (!a.Expr.GetAttributableValue (ec, member.Type, out value))
 588                                                 return false;
 589
 590                                         PropertyBase pb = TypeManager.GetProperty (pi);
 591                                         if (pb != null)
 592                                                 obsolete_attr = pb.GetObsoleteAttribute ();
 593                                         else
 594                                                 obsolete_attr = AttributeTester.GetMemberObsoleteAttribute (pi);
 595
 596                                         prop_values.Add (value);
 597                                         prop_infos.Add (pi);
 598
 599                                 } else {
 600                                         var fi = ((FieldExpr) member).Spec;
 601
 602                                         if (fi.IsReadOnly || fi.IsStatic) {
 603                                                 Error_InvalidNamedArgument (ec, a);
 604                                                 return false;
 605                                         }
 606
 607                                         if (!IsValidArgumentType (member.Type)) {
 608                                                 ec.Report.SymbolRelatedToPreviousError (fi.MetaInfo);
 609                                                 Error_InvalidNamedArgumentType (ec, a);
 610                                                 return false;
 611                                         }
 612
 613                                         object value;
 614                                         if (!a.Expr.GetAttributableValue (ec, member.Type, out value))
 615                                                 return false;
 616
 617                                         FieldBase fb = TypeManager.GetField (fi.MetaInfo);
 618                                         if (fb != null)
 619                                                 obsolete_attr = fb.GetObsoleteAttribute ();
 620                                         else
 621                                                 obsolete_attr = AttributeTester.GetMemberObsoleteAttribute (fi.MetaInfo);
 622
 623                                         field_values.Add (value);
 624                                         field_infos.Add (fi.MetaInfo);
 625                                 }
 626
 627                                 if (obsolete_attr != null && !context.IsObsolete)
 628                                         AttributeTester.Report_ObsoleteMessage (obsolete_attr, member.GetSignatureForError (), member.Location, Report);
 629                         }
 630
 631                         prop_info_arr = new PropertyInfo [prop_infos.Count];
 632                         field_info_arr = new FieldInfo [field_infos.Count];
 633                         field_values_arr = new object [field_values.Count];
 634                         prop_values_arr = new object [prop_values.Count];
 635
 636                         field_infos.CopyTo  (field_info_arr, 0);
 637                         field_values.CopyTo (field_values_arr, 0);
 638
 639                         prop_values.CopyTo  (prop_values_arr, 0);
 640                         prop_infos.CopyTo   (prop_info_arr, 0);
 641
 642                         return true;
 643                 }
 644
 645                 /// <summary>
 646                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 647                 /// </summary>
 648                 public string GetValidTargets ()
 649                 {
 650                         StringBuilder sb = new StringBuilder ();
 651                         AttributeTargets targets = GetAttributeUsage (Type).ValidOn;
 652
 653                         if ((targets & AttributeTargets.Assembly) != 0)
 654                                 sb.Append ("assembly, ");
 655
 656                         if ((targets & AttributeTargets.Module) != 0)
 657                                 sb.Append ("module, ");
 658
 659                         if ((targets & AttributeTargets.Class) != 0)
 660                                 sb.Append ("class, ");
 661
 662                         if ((targets & AttributeTargets.Struct) != 0)
 663                                 sb.Append ("struct, ");
 664
 665                         if ((targets & AttributeTargets.Enum) != 0)
 666                                 sb.Append ("enum, ");
 667
 668                         if ((targets & AttributeTargets.Constructor) != 0)
 669                                 sb.Append ("constructor, ");
 670
 671                         if ((targets & AttributeTargets.Method) != 0)
 672                                 sb.Append ("method, ");
 673
 674                         if ((targets & AttributeTargets.Property) != 0)
 675                                 sb.Append ("property, indexer, ");
 676
 677                         if ((targets & AttributeTargets.Field) != 0)
 678                                 sb.Append ("field, ");
 679
 680                         if ((targets & AttributeTargets.Event) != 0)
 681                                 sb.Append ("event, ");
 682
 683                         if ((targets & AttributeTargets.Interface) != 0)
 684                                 sb.Append ("interface, ");
 685
 686                         if ((targets & AttributeTargets.Parameter) != 0)
 687                                 sb.Append ("parameter, ");
 688
 689                         if ((targets & AttributeTargets.Delegate) != 0)
 690                                 sb.Append ("delegate, ");
 691
 692                         if ((targets & AttributeTargets.ReturnValue) != 0)
 693                                 sb.Append ("return, ");
 694
 695                         if ((targets & AttributeTargets.GenericParameter) != 0)
 696                                 sb.Append ("type parameter, ");
 697
 698                         return sb.Remove (sb.Length - 2, 2).ToString ();
 699                 }
 700
 701                 /// <summary>
 702                 /// Returns AttributeUsage attribute based on types hierarchy
 703                 /// </summary>
 704                 static AttributeUsageAttribute GetAttributeUsage (Type type)
 705                 {
 706                         AttributeUsageAttribute ua;
 707                         if (usage_attr_cache.TryGetValue (type, out ua))
 708                                 return ua;
 709
 710                         Class attr_class = TypeManager.LookupClass (type);
 711                         PredefinedAttribute pa = PredefinedAttributes.Get.AttributeUsage;
 712
 713                         if (attr_class == null) {
 714                                 if (!pa.IsDefined)
 715                                         return new AttributeUsageAttribute (0);
 716
 717                                 object[] usage_attr = type.GetCustomAttributes (pa.Type, true);
 718                                 ua = (AttributeUsageAttribute)usage_attr [0];
 719                                 usage_attr_cache.Add (type, ua);
 720                                 return ua;
 721                         }
 722
 723                         Attribute a = null;
 724                         if (attr_class.OptAttributes != null)
 725                                 a = attr_class.OptAttributes.Search (pa);
 726
 727                         if (a == null) {
 728                                 if (attr_class.TypeBuilder.BaseType != TypeManager.attribute_type)
 729                                         ua = GetAttributeUsage (attr_class.TypeBuilder.BaseType);
 730                                 else
 731                                         ua = DefaultUsageAttribute;
 732                         } else {
 733                                 ua = a.GetAttributeUsageAttribute ();
 734                         }
 735
 736                         usage_attr_cache.Add (type, ua);
 737                         return ua;
 738                 }
 739
 740                 AttributeUsageAttribute GetAttributeUsageAttribute ()
 741                 {
 742                         if (pos_values == null)
 743                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 744                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 745                                 Resolve ();
 746
 747                         if (resolve_error)
 748                                 return DefaultUsageAttribute;
 749
 750                         AttributeUsageAttribute usage_attribute = new AttributeUsageAttribute ((AttributeTargets)pos_values [0]);
 751
 752                         object field = GetPropertyValue ("AllowMultiple");
 753                         if (field != null)
 754                                 usage_attribute.AllowMultiple = (bool)field;
 755
 756                         field = GetPropertyValue ("Inherited");
 757                         if (field != null)
 758                                 usage_attribute.Inherited = (bool)field;
 759
 760                         return usage_attribute;
 761                 }
 762
 763                 /// <summary>
 764                 /// Returns custom name of indexer
 765                 /// </summary>
 766                 public string GetIndexerAttributeValue ()
 767                 {
 768                         if (pos_values == null)
 769                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 770                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 771                                 Resolve ();
 772
 773                         if (resolve_error)
 774                                 return null;
 775
 776                         return pos_values [0] as string;
 777                 }
 778
 779                 /// <summary>
 780                 /// Returns condition of ConditionalAttribute
 781                 /// </summary>
 782                 public string GetConditionalAttributeValue ()
 783                 {
 784                         if (pos_values == null)
 785                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 786                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 787                                 Resolve ();
 788
 789                         if (resolve_error)
 790                                 return null;
 791
 792                         return (string)pos_values [0];
 793                 }
 794
 795                 /// <summary>
 796                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 797                 /// </summary>
 798                 public ObsoleteAttribute GetObsoleteAttribute ()
 799                 {
 800                         if (pos_values == null)
 801                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 802                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 803                                 Resolve ();
 804
 805                         if (resolve_error)
 806                                 return null;
 807
 808                         if (pos_values == null || pos_values.Length == 0)
 809                                 return new ObsoleteAttribute ();
 810
 811                         if (pos_values.Length == 1)
 812                                 return new ObsoleteAttribute ((string)pos_values [0]);
 813
 814                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 815                 }
 816
 817                 /// <summary>
 818                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 819                 /// before ApplyAttribute. We need to resolve the arguments.
 820                 /// This situation occurs when class deps is differs from Emit order.
 821                 /// </summary>
 822                 public bool GetClsCompliantAttributeValue ()
 823                 {
 824                         if (pos_values == null)
 825                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 826                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 827                                 Resolve ();
 828
 829                         if (resolve_error)
 830                                 return false;
 831
 832                         return (bool)pos_values [0];
 833                 }
 834
 835                 public Type GetCoClassAttributeValue ()
 836                 {
 837                         if (pos_values == null)
 838                                 Resolve ();
 839
 840                         if (resolve_error)
 841                                 return null;
 842
 843                         return (Type)pos_values [0];
 844                 }
 845
 846                 public bool CheckTarget ()
 847                 {
 848                         string[] valid_targets = Owner.ValidAttributeTargets;
 849                         if (ExplicitTarget == null || ExplicitTarget == valid_targets [0]) {
 850                                 Target = Owner.AttributeTargets;
 851                                 return true;
 852                         }
 853
 854                         // TODO: we can skip the first item
 855                         if (Array.Exists (valid_targets, i => i == ExplicitTarget)) {
 856                                 switch (ExplicitTarget) {
 857                                 case "return": Target = AttributeTargets.ReturnValue; return true;
 858                                 case "param": Target = AttributeTargets.Parameter; return true;
 859                                 case "field": Target = AttributeTargets.Field; return true;
 860                                 case "method": Target = AttributeTargets.Method; return true;
 861                                 case "property": Target = AttributeTargets.Property; return true;
 862                                 }
 863                                 throw new InternalErrorException ("Unknown explicit target: " + ExplicitTarget);
 864                         }
 865
 866                         StringBuilder sb = new StringBuilder ();
 867                         foreach (string s in valid_targets) {
 868                                 sb.Append (s);
 869                                 sb.Append (", ");
 870                         }
 871                         sb.Remove (sb.Length - 2, 2);
 872                         Report.Error (657, Location, "`{0}' is not a valid attribute location for this declaration. " +
 873                                 "Valid attribute locations for this declaration are `{1}'", ExplicitTarget, sb.ToString ());
 874                         return false;
 875                 }
 876
 877                 /// <summary>
 878                 /// Tests permitted SecurityAction for assembly or other types
 879                 /// </summary>
 880                 protected virtual bool IsSecurityActionValid (bool for_assembly)
 881                 {
 882                         SecurityAction action = GetSecurityActionValue ();
 883
 884                         switch (action) {
 885                         case SecurityAction.Demand:
 886                         case SecurityAction.Assert:
 887                         case SecurityAction.Deny:
 888                         case SecurityAction.PermitOnly:
 889                         case SecurityAction.LinkDemand:
 890                         case SecurityAction.InheritanceDemand:
 891                                 if (!for_assembly)
 892                                         return true;
 893                                 break;
 894
 895                         case SecurityAction.RequestMinimum:
 896                         case SecurityAction.RequestOptional:
 897                         case SecurityAction.RequestRefuse:
 898                                 if (for_assembly)
 899                                         return true;
 900                                 break;
 901
 902                         default:
 903                                 Error_AttributeEmitError ("SecurityAction is out of range");
 904                                 return false;
 905                         }
 906
 907                         Error_AttributeEmitError (String.Concat ("SecurityAction `", action, "' is not valid for this declaration"));
 908                         return false;
 909                 }
 910
 911                 System.Security.Permissions.SecurityAction GetSecurityActionValue ()
 912                 {
 913                         return (SecurityAction)pos_values [0];
 914                 }
 915
 916                 /// <summary>
 917                 /// Creates instance of SecurityAttribute class and add result of CreatePermission method to permission table.
 918                 /// </summary>
 919                 /// <returns></returns>
 920                 public void ExtractSecurityPermissionSet (Dictionary<SecurityAction, PermissionSet> permissions)
 921                 {
 922                         Type orig_assembly_type = null;
 923
 924                         if (TypeManager.LookupDeclSpace (Type) != null) {
 925                                 if (!RootContext.StdLib) {
 926                                         orig_assembly_type = Type.GetType (Type.FullName);
 927                                 } else {
 928                                         string orig_version_path = Environment.GetEnvironmentVariable ("__SECURITY_BOOTSTRAP_DB");
 929                                         if (orig_version_path == null) {
 930                                                 Error_AttributeEmitError ("security custom attributes can not be referenced from defining assembly");
 931                                                 return;
 932                                         }
 933
 934                                         if (orig_sec_assembly == null) {
 935                                                 string file = Path.Combine (orig_version_path, Driver.OutputFile);
 936                                                 orig_sec_assembly = Assembly.LoadFile (file);
 937                                         }
 938
 939                                         orig_assembly_type = orig_sec_assembly.GetType (Type.FullName, true);
 940                                         if (orig_assembly_type == null) {
 941                                                 Report.Warning (-112, 1, Location, "Self-referenced security attribute `{0}' " +
 942                                                                 "was not found in previous version of assembly");
 943                                                 return;
 944                                         }
 945                                 }
 946                         }
 947
 948                         SecurityAttribute sa;
 949                         // For all non-selfreferencing security attributes we can avoid all hacks
 950                         if (orig_assembly_type == null) {
 951                                 sa = (SecurityAttribute) Activator.CreateInstance (Type, pos_values);
 952
 953                                 if (prop_info_arr != null) {
 954                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 955                                                 PropertyInfo pi = prop_info_arr [i];
 956                                                 pi.SetValue (sa, prop_values_arr [i], null);
 957                                         }
 958                                 }
 959                         } else {
 960                                 // HACK: All security attributes have same ctor syntax
 961                                 sa = (SecurityAttribute) Activator.CreateInstance (orig_assembly_type, new object[] { GetSecurityActionValue () } );
 962
 963                                 // All types are from newly created assembly but for invocation with old one we need to convert them
 964                                 if (prop_info_arr != null) {
 965                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 966                                                 PropertyInfo emited_pi = prop_info_arr [i];
 967                                                 // FIXME: We are missing return type filter
 968                                                 // TODO: pi can be null
 969                                                 PropertyInfo pi = orig_assembly_type.GetProperty (emited_pi.Name);
 970
 971                                                 object old_instance = TypeManager.IsEnumType (pi.PropertyType) ?
 972                                                         System.Enum.ToObject (pi.PropertyType, prop_values_arr [i]) :
 973                                                         prop_values_arr [i];
 974
 975                                                 pi.SetValue (sa, old_instance, null);
 976                                         }
 977                                 }
 978                         }
 979
 980                         IPermission perm;
 981                         perm = sa.CreatePermission ();
 982                         SecurityAction action = GetSecurityActionValue ();
 983
 984                         // IS is correct because for corlib we are using an instance from old corlib
 985                         if (!(perm is System.Security.CodeAccessPermission)) {
 986                                 switch (action) {
 987                                 case SecurityAction.Demand:
 988                                         action = (SecurityAction)13;
 989                                         break;
 990                                 case SecurityAction.LinkDemand:
 991                                         action = (SecurityAction)14;
 992                                         break;
 993                                 case SecurityAction.InheritanceDemand:
 994                                         action = (SecurityAction)15;
 995                                         break;
 996                                 }
 997                         }
 998
 999                         PermissionSet ps;
1000                         if (!permissions.TryGetValue (action, out ps)) {
1001                                 if (sa is PermissionSetAttribute)
1002                                         ps = new PermissionSet (sa.Unrestricted ? PermissionState.Unrestricted : PermissionState.None);
1003                                 else
1004                                         ps = new PermissionSet (PermissionState.None);
1005
1006                                 permissions.Add (action, ps);
1007                         } else if (!ps.IsUnrestricted () && (sa is PermissionSetAttribute) && sa.Unrestricted) {
1008                                 ps = ps.Union (new PermissionSet (PermissionState.Unrestricted));
1009                                 permissions [action] = ps;
1010                         }
1011                         ps.AddPermission (perm);
1012                 }
1013
1014                 public object GetPropertyValue (string name)
1015                 {
1016                         if (prop_info_arr == null)
1017                                 return null;
1018
1019                         for (int i = 0; i < prop_info_arr.Length; ++i) {
1020                                 if (prop_info_arr [i].Name == name)
1021                                         return prop_values_arr [i];
1022                         }
1023
1024                         return null;
1025                 }
1026
1027                 //
1028                 // Theoretically, we can get rid of this, since FieldBuilder.SetCustomAttribute()
1029                 // and ParameterBuilder.SetCustomAttribute() are supposed to handle this attribute.
1030                 // However, we can't, since it appears that the .NET 1.1 SRE hangs when given a MarshalAsAttribute.
1031                 //
1032 #if false
1033                 public UnmanagedMarshal GetMarshal (Attributable attr)
1034                 {
1035                         UnmanagedType UnmanagedType;
1036                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (UnmanagedType))
1037                                 UnmanagedType = (UnmanagedType) System.Enum.ToObject (typeof (UnmanagedType), pos_values [0]);
1038                         else
1039                                 UnmanagedType = (UnmanagedType) pos_values [0];
1040
1041                         object value = GetFieldValue ("SizeParamIndex");
1042                         if (value != null && UnmanagedType != UnmanagedType.LPArray) {
1043                                 Error_AttributeEmitError ("SizeParamIndex field is not valid for the specified unmanaged type");
1044                                 return null;
1045                         }
1046
1047                         object o = GetFieldValue ("ArraySubType");
1048                         UnmanagedType array_sub_type = o == null ? (UnmanagedType) 0x50 /* NATIVE_MAX */ : (UnmanagedType) o;
1049
1050                         switch (UnmanagedType) {
1051                         case UnmanagedType.CustomMarshaler: {
1052                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
1053                                         BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
1054                                 if (define_custom == null) {
1055                                         Report.RuntimeMissingSupport (Location, "set marshal info");
1056                                         return null;
1057                                 }
1058
1059                                 object [] args = new object [4];
1060                                 args [0] = GetFieldValue ("MarshalTypeRef");
1061                                 args [1] = GetFieldValue ("MarshalCookie");
1062                                 args [2] = GetFieldValue ("MarshalType");
1063                                 args [3] = Guid.Empty;
1064                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
1065                         }
1066                         case UnmanagedType.LPArray: {
1067                                 object size_const = GetFieldValue ("SizeConst");
1068                                 object size_param_index = GetFieldValue ("SizeParamIndex");
1069
1070                                 if ((size_const != null) || (size_param_index != null)) {
1071                                         MethodInfo define_array = typeof (UnmanagedMarshal).GetMethod ("DefineLPArrayInternal",
1072                                                 BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
1073                                         if (define_array == null) {
1074                                                 Report.RuntimeMissingSupport (Location, "set marshal info");
1075                                                 return null;
1076                                         }
1077
1078                                         object [] args = new object [3];
1079                                         args [0] = array_sub_type;
1080                                         args [1] = size_const == null ? -1 : size_const;
1081                                         args [2] = size_param_index == null ? -1 : size_param_index;
1082                                         return (UnmanagedMarshal) define_array.Invoke (null, args);
1083                                 }
1084                                 else
1085                                         return UnmanagedMarshal.DefineLPArray (array_sub_type);
1086                         }
1087                         case UnmanagedType.SafeArray:
1088                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
1089
1090                         case UnmanagedType.ByValArray:
1091                                 FieldBase fm = attr as FieldBase;
1092                                 if (fm == null) {
1093                                         Error_AttributeEmitError ("Specified unmanaged type is only valid on fields");
1094                                         return null;
1095                                 }
1096                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
1097
1098                         case UnmanagedType.ByValTStr:
1099                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
1100
1101                         default:
1102                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
1103                         }
1104                 }
1105
1106                 object GetFieldValue (string name)
1107                 {
1108                         int i;
1109                         if (field_info_arr == null)
1110                                 return null;
1111                         i = 0;
1112                         foreach (FieldInfo fi in field_info_arr) {
1113                                 if (fi.Name == name)
1114                                         return GetValue (field_values_arr [i]);
1115                                 i++;
1116                         }
1117                         return null;
1118                 }
1119
1120                 static object GetValue (object value)
1121                 {
1122                         if (value is EnumConstant)
1123                                 return ((EnumConstant) value).GetValue ();
1124                         else
1125                                 return value;
1126                 }
1127
1128 #endif
1129
1130                 public CharSet GetCharSetValue ()
1131                 {
1132                         return (CharSet)System.Enum.Parse (typeof (CharSet), pos_values [0].ToString ());
1133                 }
1134
1135                 public bool HasField (string fieldName)
1136                 {
1137                         if (field_info_arr == null)
1138                                 return false;
1139
1140                         foreach (FieldInfo fi in field_info_arr) {
1141                                 if (fi.Name == fieldName)
1142                                         return true;
1143                         }
1144
1145                         return false;
1146                 }
1147
1148                 public bool IsInternalMethodImplAttribute {
1149                         get {
1150                                 if (Type != PredefinedAttributes.Get.MethodImpl)
1151                                         return false;
1152
1153                                 MethodImplOptions options;
1154                                 if (pos_values[0].GetType () != typeof (MethodImplOptions))
1155                                         options = (MethodImplOptions)System.Enum.ToObject (typeof (MethodImplOptions), pos_values[0]);
1156                                 else
1157                                         options = (MethodImplOptions)pos_values[0];
1158
1159                                 return (options & MethodImplOptions.InternalCall) != 0;
1160                         }
1161                 }
1162
1163                 public LayoutKind GetLayoutKindValue ()
1164                 {
1165                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (LayoutKind))
1166                                 return (LayoutKind)System.Enum.ToObject (typeof (LayoutKind), pos_values [0]);
1167
1168                         return (LayoutKind)pos_values [0];
1169                 }
1170
1171                 public object GetParameterDefaultValue ()
1172                 {
1173                         return pos_values [0];
1174                 }
1175
1176                 public override bool Equals (object obj)
1177                 {
1178                         Attribute a = obj as Attribute;
1179                         if (a == null)
1180                                 return false;
1181
1182                         return Type == a.Type && Target == a.Target;
1183                 }
1184
1185                 public override int GetHashCode ()
1186                 {
1187                         return type.GetHashCode () ^ Target.GetHashCode ();
1188                 }
1189
1190                 /// <summary>
1191                 /// Emit attribute for Attributable symbol
1192                 /// </summary>
1193                 public void Emit (Dictionary<Attribute, List<Attribute>> allEmitted)
1194                 {
1195                         CustomAttributeBuilder cb = Resolve ();
1196                         if (cb == null)
1197                                 return;
1198
1199                         AttributeUsageAttribute usage_attr = GetAttributeUsage (Type);
1200                         if ((usage_attr.ValidOn & Target) == 0) {
1201                                 Report.Error (592, Location, "The attribute `{0}' is not valid on this declaration type. " +
1202                                               "It is valid on `{1}' declarations only",
1203                                         GetSignatureForError (), GetValidTargets ());
1204                                 return;
1205                         }
1206
1207                         var predefined = PredefinedAttributes.Get;
1208
1209                         try {
1210                                 foreach (Attributable target in targets)
1211                                         target.ApplyAttributeBuilder (this, cb, predefined);
1212                         } catch (Exception e) {
1213                                 Error_AttributeEmitError (e.Message);
1214                                 return;
1215                         }
1216
1217                         if (!usage_attr.AllowMultiple && allEmitted != null) {
1218                                 if (allEmitted.ContainsKey (this)) {
1219                                         var a = allEmitted [this];
1220                                         if (a == null) {
1221                                                 a = new List<Attribute> (2);
1222                                                 allEmitted [this] = a;
1223                                         }
1224                                         a.Add (this);
1225                                 } else {
1226                                         allEmitted.Add (this, null);
1227                                 }
1228                         }
1229
1230                         if (!RootContext.VerifyClsCompliance)
1231                                 return;
1232
1233                         // Here we are testing attribute arguments for array usage (error 3016)
1234                         if (Owner.IsClsComplianceRequired ()) {
1235                                 if (PosArguments != null)
1236                                         PosArguments.CheckArrayAsAttribute (context.Compiler);
1237
1238                                 if (NamedArguments == null)
1239                                         return;
1240
1241                                 NamedArguments.CheckArrayAsAttribute (context.Compiler);
1242                         }
1243                 }
1244
1245                 private Expression GetValue ()
1246                 {
1247                         if (PosArguments == null || PosArguments.Count < 1)
1248                                 return null;
1249
1250                         return PosArguments [0].Expr;
1251                 }
1252
1253                 public string GetString ()
1254                 {
1255                         Expression e = GetValue ();
1256                         if (e is StringConstant)
1257                                 return ((StringConstant)e).Value;
1258                         return null;
1259                 }
1260
1261                 public bool GetBoolean ()
1262                 {
1263                         Expression e = GetValue ();
1264                         if (e is BoolConstant)
1265                                 return ((BoolConstant)e).Value;
1266                         return false;
1267                 }
1268
1269                 public Type GetArgumentType ()
1270                 {
1271                         TypeOf e = GetValue () as TypeOf;
1272                         if (e == null)
1273                                 return null;
1274                         return e.TypeArgument;
1275                 }
1276
1277                 public override Expression CreateExpressionTree (ResolveContext ec)
1278                 {
1279                         throw new NotSupportedException ("ET");
1280                 }
1281
1282                 protected override Expression DoResolve (ResolveContext ec)
1283                 {
1284                         throw new NotImplementedException ();
1285                 }
1286
1287                 public override void Emit (EmitContext ec)
1288                 {
1289                         throw new NotImplementedException ();
1290                 }
1291         }
1292
1293
1294         /// <summary>
1295         /// For global attributes (assembly, module) we need special handling.
1296         /// Attributes can be located in the several files
1297         /// </summary>
1298         public class GlobalAttribute : Attribute
1299         {
1300                 public readonly NamespaceEntry ns;
1301
1302                 public GlobalAttribute (NamespaceEntry ns, string target, ATypeNameExpression expression,
1303                                         Arguments[] args, Location loc, bool nameEscaped):
1304                         base (target, expression, args, loc, nameEscaped)
1305                 {
1306                         this.ns = ns;
1307                 }
1308
1309                 public override void AttachTo (Attributable target, IMemberContext context)
1310                 {
1311                         if (ExplicitTarget == "assembly") {
1312                                 base.AttachTo (CodeGen.Assembly, context);
1313                                 return;
1314                         }
1315
1316                         if (ExplicitTarget == "module") {
1317                                 base.AttachTo (RootContext.ToplevelTypes, context);
1318                                 return;
1319                         }
1320
1321                         throw new NotImplementedException ("Unknown global explicit target " + ExplicitTarget);
1322                 }
1323
1324                 void Enter ()
1325                 {
1326                         // RootContext.ToplevelTypes has a single NamespaceEntry which gets overwritten
1327                         // each time a new file is parsed.  However, we need to use the NamespaceEntry
1328                         // in effect where the attribute was used.  Since code elsewhere cannot assume
1329                         // that the NamespaceEntry is right, just overwrite it.
1330                         //
1331                         // Precondition: RootContext.ToplevelTypes == null
1332
1333                         if (RootContext.ToplevelTypes.NamespaceEntry != null)
1334                                 throw new InternalErrorException (Location + " non-null NamespaceEntry");
1335
1336                         RootContext.ToplevelTypes.NamespaceEntry = ns;
1337                 }
1338
1339                 protected override bool IsSecurityActionValid (bool for_assembly)
1340                 {
1341                         return base.IsSecurityActionValid (true);
1342                 }
1343
1344                 void Leave ()
1345                 {
1346                         RootContext.ToplevelTypes.NamespaceEntry = null;
1347                 }
1348
1349                 protected override TypeExpr ResolveAsTypeTerminal (Expression expr, IMemberContext ec)
1350                 {
1351                         try {
1352                                 Enter ();
1353                                 return base.ResolveAsTypeTerminal (expr, ec);
1354                         }
1355                         finally {
1356                                 Leave ();
1357                         }
1358                 }
1359
1360                 protected override ConstructorInfo ResolveConstructor (ResolveContext ec)
1361                 {
1362                         try {
1363                                 Enter ();
1364                                 return base.ResolveConstructor (ec);
1365                         }
1366                         finally {
1367                                 Leave ();
1368                         }
1369                 }
1370
1371                 protected override bool ResolveNamedArguments (ResolveContext ec)
1372                 {
1373                         try {
1374                                 Enter ();
1375                                 return base.ResolveNamedArguments (ec);
1376                         }
1377                         finally {
1378                                 Leave ();
1379                         }
1380                 }
1381         }
1382
1383         public class Attributes {
1384                 public readonly List<Attribute> Attrs;
1385
1386                 public Attributes (Attribute a)
1387                 {
1388                         Attrs = new List<Attribute> ();
1389                         Attrs.Add (a);
1390                 }
1391
1392                 public Attributes (List<Attribute> attrs)
1393                 {
1394                         Attrs = attrs;
1395                 }
1396
1397                 public void AddAttributes (List<Attribute> attrs)
1398                 {
1399                         Attrs.AddRange (attrs);
1400                 }
1401
1402                 public void AttachTo (Attributable attributable, IMemberContext context)
1403                 {
1404                         foreach (Attribute a in Attrs)
1405                                 a.AttachTo (attributable, context);
1406                 }
1407
1408                 public Attributes Clone ()
1409                 {
1410                         var al = new List<Attribute> (Attrs.Count);
1411                         foreach (Attribute a in Attrs)
1412                                 al.Add (a.Clone ());
1413
1414                         return new Attributes (al);
1415                 }
1416
1417                 /// <summary>
1418                 /// Checks whether attribute target is valid for the current element
1419                 /// </summary>
1420                 public bool CheckTargets ()
1421                 {
1422                         foreach (Attribute a in Attrs) {
1423                                 if (!a.CheckTarget ())
1424                                         return false;
1425                         }
1426                         return true;
1427                 }
1428
1429                 public Attribute Search (PredefinedAttribute t)
1430                 {
1431                         foreach (Attribute a in Attrs) {
1432                                 if (a.ResolveType () == t)
1433                                         return a;
1434                         }
1435                         return null;
1436                 }
1437
1438                 /// <summary>
1439                 /// Returns all attributes of type 't'. Use it when attribute is AllowMultiple = true
1440                 /// </summary>
1441                 public Attribute[] SearchMulti (PredefinedAttribute t)
1442                 {
1443                         List<Attribute> ar = null;
1444
1445                         foreach (Attribute a in Attrs) {
1446                                 if (a.ResolveType () == t) {
1447                                         if (ar == null)
1448                                                 ar = new List<Attribute> (Attrs.Count);
1449                                         ar.Add (a);
1450                                 }
1451                         }
1452
1453                         return ar == null ? null : ar.ToArray ();
1454                 }
1455
1456                 public void Emit ()
1457                 {
1458                         CheckTargets ();
1459
1460                         Dictionary<Attribute, List<Attribute>> ld = Attrs.Count > 1 ? new Dictionary<Attribute, List<Attribute>> () : null;
1461
1462                         foreach (Attribute a in Attrs)
1463                                 a.Emit (ld);
1464
1465                         if (ld == null || ld.Count == 0)
1466                                 return;
1467
1468                         foreach (var d in ld) {
1469                                 if (d.Value == null)
1470                                         continue;
1471
1472                                 Attribute a = d.Key;
1473
1474                                 foreach (Attribute collision in d.Value)
1475                                         a.Report.SymbolRelatedToPreviousError (collision.Location, "");
1476
1477                                 a.Report.Error (579, a.Location, "The attribute `{0}' cannot be applied multiple times",
1478                                         a.GetSignatureForError ());
1479                         }
1480                 }
1481
1482                 public bool Contains (PredefinedAttribute t)
1483                 {
1484                         return Search (t) != null;
1485                 }
1486         }
1487
1488         /// <summary>
1489         /// Helper class for attribute verification routine.
1490         /// </summary>
1491         sealed class AttributeTester
1492         {
1493                 static Dictionary<Type, bool> analyzed_types;
1494                 static Dictionary<Type, ObsoleteAttribute> analyzed_types_obsolete;
1495                 static Dictionary<MemberInfo, ObsoleteAttribute> analyzed_member_obsolete;
1496                 static Dictionary<MethodBase, bool> analyzed_method_excluded;
1497 //              static Dictionary<FieldInfo, IFixedBuffer> fixed_buffer_cache;
1498
1499                 static AttributeTester ()
1500                 {
1501                         Reset ();
1502                 }
1503
1504                 private AttributeTester ()
1505                 {
1506                 }
1507
1508                 public static void Reset ()
1509                 {
1510                         analyzed_types = new Dictionary<Type, bool> (ReferenceEquality<Type>.Default);
1511                         analyzed_types_obsolete = new Dictionary<Type, ObsoleteAttribute> (ReferenceEquality<Type>.Default);
1512                         analyzed_member_obsolete = new Dictionary<MemberInfo, ObsoleteAttribute> (ReferenceEquality<MemberInfo>.Default);
1513                         analyzed_method_excluded = new Dictionary<MethodBase, bool> (ReferenceEquality<MethodBase>.Default);
1514 //                      fixed_buffer_cache = new Dictionary<FieldInfo, IFixedBuffer> (ReferenceEquality<FieldInfo>.Default);
1515                 }
1516
1517                 public enum Result {
1518                         Ok,
1519                         RefOutArrayError,
1520                         ArrayArrayError
1521                 }
1522
1523                 /// <summary>
1524                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1525                 /// It tests differing only in ref or out, or in array rank.
1526                 /// </summary>
1527                 public static Result AreOverloadedMethodParamsClsCompliant (AParametersCollection pa, AParametersCollection pb)
1528                 {
1529                         Type [] types_a = pa.Types;
1530                         Type [] types_b = pb.Types;
1531                         if (types_a == null || types_b == null)
1532                                 return Result.Ok;
1533
1534                         if (types_a.Length != types_b.Length)
1535                                 return Result.Ok;
1536
1537                         Result result = Result.Ok;
1538                         for (int i = 0; i < types_b.Length; ++i) {
1539                                 Type aType = types_a [i];
1540                                 Type bType = types_b [i];
1541
1542                                 if (aType.IsArray && bType.IsArray) {
1543                                         Type a_el_type = TypeManager.GetElementType (aType);
1544                                         Type b_el_type = TypeManager.GetElementType (bType);
1545                                         if (aType.GetArrayRank () != bType.GetArrayRank () && a_el_type == b_el_type) {
1546                                                 result = Result.RefOutArrayError;
1547                                                 continue;
1548                                         }
1549
1550                                         if (a_el_type.IsArray || b_el_type.IsArray) {
1551                                                 result = Result.ArrayArrayError;
1552                                                 continue;
1553                                         }
1554                                 }
1555
1556                                 if (aType != bType)
1557                                         return Result.Ok;
1558
1559                                 const Parameter.Modifier out_ref_mod = (Parameter.Modifier.OUTMASK | Parameter.Modifier.REFMASK);
1560                                 if ((pa.FixedParameters[i].ModFlags & out_ref_mod) != (pb.FixedParameters[i].ModFlags & out_ref_mod))
1561                                         result = Result.RefOutArrayError;
1562                         }
1563                         return result;
1564                 }
1565
1566                 /// <summary>
1567                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1568                 /// </summary>
1569                 public static bool IsClsCompliant (Type type)
1570                 {
1571                         if (type == null)
1572                                 return true;
1573
1574                         bool result;
1575                         if (analyzed_types.TryGetValue (type, out result))
1576                                 return result;
1577
1578                         if (type.IsPointer) {
1579                                 analyzed_types.Add (type, false);
1580                                 return false;
1581                         }
1582
1583                         if (type.IsArray) {
1584                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1585                         } else if (TypeManager.IsNullableType (type)) {
1586                                 result = IsClsCompliant (TypeManager.TypeToCoreType (TypeManager.GetTypeArguments (type) [0]));
1587                         } else {
1588                                 result = AnalyzeTypeCompliance (type);
1589                         }
1590                         analyzed_types.Add (type, result);
1591                         return result;
1592                 }
1593
1594                 public static void VerifyModulesClsCompliance (CompilerContext ctx)
1595                 {
1596                         Module[] modules = GlobalRootNamespace.Instance.Modules;
1597                         if (modules == null)
1598                                 return;
1599
1600                         // The first module is generated assembly
1601                         for (int i = 1; i < modules.Length; ++i) {
1602                                 Module module = modules [i];
1603                                 if (!GetClsCompliantAttributeValue (module, null)) {
1604                                         ctx.Report.Error (3013, "Added modules must be marked with the CLSCompliant attribute " +
1605                                                       "to match the assembly", module.Name);
1606                                         return;
1607                                 }
1608                         }
1609                 }
1610
1611                 public static Type GetImportedIgnoreCaseClsType (string name)
1612                 {
1613                         foreach (Assembly a in GlobalRootNamespace.Instance.Assemblies) {
1614                                 Type t = a.GetType (name, false, true);
1615                                 if (t == null)
1616                                         continue;
1617
1618                                 if (IsClsCompliant (t))
1619                                         return t;
1620                         }
1621                         return null;
1622                 }
1623
1624                 static bool GetClsCompliantAttributeValue (ICustomAttributeProvider attribute_provider, Assembly a)
1625                 {
1626                         PredefinedAttribute pa = PredefinedAttributes.Get.CLSCompliant;
1627                         if (!pa.IsDefined)
1628                                 return false;
1629
1630                         object[] cls_attr = attribute_provider.GetCustomAttributes (pa.Type, false);
1631                         if (cls_attr.Length == 0) {
1632                                 if (a == null)
1633                                         return false;
1634
1635                                 return GetClsCompliantAttributeValue (a, null);
1636                         }
1637
1638                         return ((CLSCompliantAttribute)cls_attr [0]).IsCompliant;
1639                 }
1640
1641                 static bool AnalyzeTypeCompliance (Type type)
1642                 {
1643                         type = TypeManager.DropGenericTypeArguments (type);
1644                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1645                         if (ds != null) {
1646                                 return ds.IsClsComplianceRequired ();
1647                         }
1648
1649                         if (TypeManager.IsGenericParameter (type))
1650                                 return true;
1651
1652                         return GetClsCompliantAttributeValue (type, type.Assembly);
1653                 }
1654
1655                 /// <summary>
1656                 /// Returns instance of ObsoleteAttribute when type is obsolete
1657                 /// </summary>
1658                 public static ObsoleteAttribute GetObsoleteAttribute (Type type)
1659                 {
1660                         ObsoleteAttribute result;
1661                         if (analyzed_types_obsolete.TryGetValue (type, out result))
1662                                 return result;
1663
1664                         if (TypeManager.HasElementType (type)) {
1665                                 result = GetObsoleteAttribute (TypeManager.GetElementType (type));
1666                         } else if (TypeManager.IsGenericParameter (type))
1667                                 result = null;  // TODO: throw new NotSupportedException ()
1668                         else if (TypeManager.IsGenericType (type) && !TypeManager.IsGenericTypeDefinition (type)) {
1669                                 return GetObsoleteAttribute (TypeManager.DropGenericTypeArguments (type));
1670                         } else {
1671                                 DeclSpace type_ds = TypeManager.LookupDeclSpace (type);
1672
1673                                 // Type is external, we can get attribute directly
1674                                 if (type_ds == null) {
1675                                         PredefinedAttribute pa = PredefinedAttributes.Get.Obsolete;
1676                                         if (pa.IsDefined) {
1677                                                 object[] attribute = type.GetCustomAttributes (pa.Type, false);
1678                                                 if (attribute.Length == 1)
1679                                                         result = (ObsoleteAttribute) attribute[0];
1680                                         }
1681                                 } else {
1682                                         result = type_ds.GetObsoleteAttribute ();
1683                                 }
1684                         }
1685
1686                         // Cannot use .Add because of corlib bootstrap
1687                         analyzed_types_obsolete [type] = result;
1688                         return result;
1689                 }
1690
1691                 /// <summary>
1692                 /// Returns instance of ObsoleteAttribute when method is obsolete
1693                 /// </summary>
1694                 public static ObsoleteAttribute GetMethodObsoleteAttribute (MethodBase mb)
1695                 {
1696                         IMethodData mc = TypeManager.GetMethod (mb);
1697                         if (mc != null)
1698                                 return mc.GetObsoleteAttribute ();
1699
1700                         // compiler generated methods are not registered by AddMethod
1701                         if (mb.DeclaringType is TypeBuilder)
1702                                 return null;
1703
1704                         MemberInfo mi = TypeManager.GetPropertyFromAccessor (mb);
1705                         if (mi != null)
1706                                 return GetMemberObsoleteAttribute (mi);
1707
1708                         mi = TypeManager.GetEventFromAccessor (mb);
1709                         if (mi != null)
1710                                 return GetMemberObsoleteAttribute (mi);
1711
1712                         return GetMemberObsoleteAttribute (mb);
1713                 }
1714
1715                 /// <summary>
1716                 /// Returns instance of ObsoleteAttribute when member is obsolete
1717                 /// </summary>
1718                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1719                 {
1720                         ObsoleteAttribute oa;
1721                         if (analyzed_member_obsolete.TryGetValue (mi, out oa))
1722                                 return oa;
1723
1724                         if ((mi.DeclaringType is TypeBuilder) || TypeManager.IsGenericType (mi.DeclaringType))
1725                                 return null;
1726
1727                         PredefinedAttribute pa = PredefinedAttributes.Get.Obsolete;
1728                         if (!pa.IsDefined)
1729                                 return null;
1730
1731                         oa = System.Attribute.GetCustomAttribute (mi, pa.Type, false) as ObsoleteAttribute;
1732                         analyzed_member_obsolete.Add (mi, oa);
1733                         return oa;
1734                 }
1735
1736                 /// <summary>
1737                 /// Common method for Obsolete error/warning reporting.
1738                 /// </summary>
1739                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc, Report Report)
1740                 {
1741                         if (oa.IsError) {
1742                                 Report.Error (619, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1743                                 return;
1744                         }
1745
1746                         if (oa.Message == null || oa.Message.Length == 0) {
1747                                 Report.Warning (612, 1, loc, "`{0}' is obsolete", member);
1748                                 return;
1749                         }
1750                         Report.Warning (618, 2, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1751                 }
1752
1753                 public static bool IsConditionalMethodExcluded (MethodBase mb, Location loc)
1754                 {
1755                         bool excluded;
1756                         if (analyzed_method_excluded.TryGetValue (mb, out excluded))
1757                                 return excluded;
1758
1759                         PredefinedAttribute pa = PredefinedAttributes.Get.Conditional;
1760                         if (!pa.IsDefined)
1761                                 return false;
1762
1763                         ConditionalAttribute[] attrs = mb.GetCustomAttributes (pa.Type, true)
1764                                 as ConditionalAttribute[];
1765                         if (attrs.Length == 0) {
1766                                 analyzed_method_excluded.Add (mb, false);
1767                                 return false;
1768                         }
1769
1770                         foreach (ConditionalAttribute a in attrs) {
1771                                 if (loc.CompilationUnit.IsConditionalDefined (a.ConditionString)) {
1772                                         analyzed_method_excluded.Add (mb, false);
1773                                         return false;
1774                                 }
1775                         }
1776
1777                         analyzed_method_excluded.Add (mb, true);
1778                         return true;
1779                 }
1780
1781                 /// <summary>
1782                 /// Analyzes class whether it has attribute which has ConditionalAttribute
1783                 /// and its condition is not defined.
1784                 /// </summary>
1785                 public static bool IsAttributeExcluded (Type type, Location loc)
1786                 {
1787                         if (!type.IsClass)
1788                                 return false;
1789
1790                         Class class_decl = TypeManager.LookupDeclSpace (type) as Class;
1791
1792                         // TODO: add caching
1793                         // TODO: merge all Type bases attribute caching to one cache to save memory
1794                         PredefinedAttribute pa = PredefinedAttributes.Get.Conditional;
1795                         if (class_decl == null && pa.IsDefined) {
1796                                 object[] attributes = type.GetCustomAttributes (pa.Type, false);
1797                                 foreach (ConditionalAttribute ca in attributes) {
1798                                         if (loc.CompilationUnit.IsConditionalDefined (ca.ConditionString))
1799                                                 return false;
1800                                 }
1801                                 return attributes.Length > 0;
1802                         }
1803
1804                         return class_decl.IsExcluded ();
1805                 }
1806
1807                 public static Type GetCoClassAttribute (Type type)
1808                 {
1809                         TypeContainer tc = TypeManager.LookupInterface (type);
1810                         PredefinedAttribute pa = PredefinedAttributes.Get.CoClass;
1811                         if (tc == null) {
1812                                 if (!pa.IsDefined)
1813                                         return null;
1814
1815                                 object[] o = type.GetCustomAttributes (pa.Type, false);
1816                                 if (o.Length < 1)
1817                                         return null;
1818                                 return ((System.Runtime.InteropServices.CoClassAttribute)o[0]).CoClass;
1819                         }
1820
1821                         if (tc.OptAttributes == null)
1822                                 return null;
1823
1824                         Attribute a = tc.OptAttributes.Search (pa);
1825                         if (a == null)
1826                                 return null;
1827
1828                         return a.GetCoClassAttributeValue ();
1829                 }
1830         }
1831
1832         public class PredefinedAttributes
1833         {
1834                 // Core types
1835                 public readonly PredefinedAttribute ParamArray;
1836                 public readonly PredefinedAttribute Out;
1837
1838                 // Optional types
1839                 public readonly PredefinedAttribute Obsolete;
1840                 public readonly PredefinedAttribute DllImport;
1841                 public readonly PredefinedAttribute MethodImpl;
1842                 public readonly PredefinedAttribute MarshalAs;
1843                 public readonly PredefinedAttribute In;
1844                 public readonly PredefinedAttribute IndexerName;
1845                 public readonly PredefinedAttribute Conditional;
1846                 public readonly PredefinedAttribute CLSCompliant;
1847                 public readonly PredefinedAttribute Security;
1848                 public readonly PredefinedAttribute Required;
1849                 public readonly PredefinedAttribute Guid;
1850                 public readonly PredefinedAttribute AssemblyCulture;
1851                 public readonly PredefinedAttribute AssemblyVersion;
1852                 public readonly PredefinedAttribute ComImport;
1853                 public readonly PredefinedAttribute CoClass;
1854                 public readonly PredefinedAttribute AttributeUsage;
1855                 public readonly PredefinedAttribute DefaultParameterValue;
1856                 public readonly PredefinedAttribute OptionalParameter;
1857
1858                 // New in .NET 2.0
1859                 public readonly PredefinedAttribute DefaultCharset;
1860                 public readonly PredefinedAttribute TypeForwarder;
1861                 public readonly PredefinedAttribute FixedBuffer;
1862                 public readonly PredefinedAttribute CompilerGenerated;
1863                 public readonly PredefinedAttribute InternalsVisibleTo;
1864                 public readonly PredefinedAttribute RuntimeCompatibility;
1865                 public readonly PredefinedAttribute DebuggerHidden;
1866                 public readonly PredefinedAttribute UnsafeValueType;
1867
1868                 // New in .NET 3.5
1869                 public readonly PredefinedAttribute Extension;
1870
1871                 // New in .NET 4.0
1872                 public readonly PredefinedAttribute Dynamic;
1873                 public readonly PredefinedAttribute DynamicTransform;   // DynamicAttribute with transform arguments
1874
1875                 //
1876                 // Optional types which are used as types and for member lookup
1877                 //
1878                 public readonly PredefinedAttribute DefaultMember;
1879                 public readonly PredefinedAttribute DecimalConstant;
1880                 public readonly PredefinedAttribute StructLayout;
1881                 public readonly PredefinedAttribute FieldOffset;
1882
1883                 public static PredefinedAttributes Get = new PredefinedAttributes ();
1884
1885                 private PredefinedAttributes ()
1886                 {
1887                         ParamArray = new PredefinedAttribute ("System", "ParamArrayAttribute");
1888                         Out = new PredefinedAttribute ("System.Runtime.InteropServices", "OutAttribute");
1889
1890                         Obsolete = new PredefinedAttribute ("System", "ObsoleteAttribute");
1891                         DllImport = new PredefinedAttribute ("System.Runtime.InteropServices", "DllImportAttribute");
1892                         MethodImpl = new PredefinedAttribute ("System.Runtime.CompilerServices", "MethodImplAttribute");
1893                         MarshalAs = new PredefinedAttribute ("System.Runtime.InteropServices", "MarshalAsAttribute");
1894                         In = new PredefinedAttribute ("System.Runtime.InteropServices", "InAttribute");
1895                         IndexerName = new PredefinedAttribute ("System.Runtime.CompilerServices", "IndexerNameAttribute");
1896                         Conditional = new PredefinedAttribute ("System.Diagnostics", "ConditionalAttribute");
1897                         CLSCompliant = new PredefinedAttribute ("System", "CLSCompliantAttribute");
1898                         Security = new PredefinedAttribute ("System.Security.Permissions", "SecurityAttribute");
1899                         Required = new PredefinedAttribute ("System.Runtime.CompilerServices", "RequiredAttributeAttribute");
1900                         Guid = new PredefinedAttribute ("System.Runtime.InteropServices", "GuidAttribute");
1901                         AssemblyCulture = new PredefinedAttribute ("System.Reflection", "AssemblyCultureAttribute");
1902                         AssemblyVersion = new PredefinedAttribute ("System.Reflection", "AssemblyVersionAttribute");
1903                         ComImport = new PredefinedAttribute ("System.Runtime.InteropServices", "ComImportAttribute");
1904                         CoClass = new PredefinedAttribute ("System.Runtime.InteropServices", "CoClassAttribute");
1905                         AttributeUsage = new PredefinedAttribute ("System", "AttributeUsageAttribute");
1906                         DefaultParameterValue = new PredefinedAttribute ("System.Runtime.InteropServices", "DefaultParameterValueAttribute");
1907                         OptionalParameter = new PredefinedAttribute ("System.Runtime.InteropServices", "OptionalAttribute");
1908
1909                         DefaultCharset = new PredefinedAttribute ("System.Runtime.InteropServices", "DefaultCharSetAttribute");
1910                         TypeForwarder = new PredefinedAttribute ("System.Runtime.CompilerServices", "TypeForwardedToAttribute");
1911                         FixedBuffer = new PredefinedAttribute ("System.Runtime.CompilerServices", "FixedBufferAttribute");
1912                         CompilerGenerated = new PredefinedAttribute ("System.Runtime.CompilerServices", "CompilerGeneratedAttribute");
1913                         InternalsVisibleTo = new PredefinedAttribute ("System.Runtime.CompilerServices", "InternalsVisibleToAttribute");
1914                         RuntimeCompatibility = new PredefinedAttribute ("System.Runtime.CompilerServices", "RuntimeCompatibilityAttribute");
1915                         DebuggerHidden = new PredefinedAttribute ("System.Diagnostics", "DebuggerHiddenAttribute");
1916                         UnsafeValueType = new PredefinedAttribute ("System.Runtime.CompilerServices", "UnsafeValueTypeAttribute");
1917
1918                         Extension = new PredefinedAttribute ("System.Runtime.CompilerServices", "ExtensionAttribute");
1919
1920                         Dynamic = new PredefinedAttribute ("System.Runtime.CompilerServices", "DynamicAttribute");
1921                         DynamicTransform = new PredefinedAttribute ("System.Runtime.CompilerServices", "DynamicAttribute");
1922
1923                         DefaultMember = new PredefinedAttribute ("System.Reflection", "DefaultMemberAttribute");
1924                         DecimalConstant = new PredefinedAttribute ("System.Runtime.CompilerServices", "DecimalConstantAttribute");
1925                         StructLayout = new PredefinedAttribute ("System.Runtime.InteropServices", "StructLayoutAttribute");
1926                         FieldOffset = new PredefinedAttribute ("System.Runtime.InteropServices", "FieldOffsetAttribute");
1927                 }
1928
1929                 public void Initialize (CompilerContext ctx)
1930                 {
1931                         foreach (FieldInfo fi in GetType ().GetFields (BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly)) {
1932                                 ((PredefinedAttribute) fi.GetValue (this)).Initialize (ctx, true);
1933                         }
1934                 }
1935
1936                 public static void Reset ()
1937                 {
1938                         Get = new PredefinedAttributes ();
1939                 }
1940         }
1941
1942         public class PredefinedAttribute
1943         {
1944                 Type type;
1945                 CustomAttributeBuilder cab;
1946                 ConstructorInfo ctor;
1947                 readonly string ns, name;
1948                 CompilerContext compiler;
1949
1950                 static readonly Type NotFound = typeof (PredefinedAttribute);
1951
1952                 public PredefinedAttribute (string ns, string name)
1953                 {
1954                         this.ns = ns;
1955                         this.name = name;
1956                 }
1957
1958                 public static bool operator == (Type type, PredefinedAttribute pa)
1959                 {
1960                         return type == pa.type;
1961                 }
1962
1963                 public static bool operator != (Type type, PredefinedAttribute pa)
1964                 {
1965                         return type != pa.type;
1966                 }
1967
1968                 public ConstructorInfo Constructor {
1969                         get { return ctor; }
1970                 }
1971
1972                 public override int GetHashCode ()
1973                 {
1974                         return base.GetHashCode ();
1975                 }
1976
1977                 public string GetSignatureForError ()
1978                 {
1979                         return ns + "." + name;
1980                 }
1981
1982                 public override bool Equals (object obj)
1983                 {
1984                         throw new NotSupportedException ();
1985                 }
1986
1987                 public void EmitAttribute (ConstructorBuilder builder)
1988                 {
1989                         if (ResolveBuilder ())
1990                                 builder.SetCustomAttribute (cab);
1991                 }
1992
1993                 public void EmitAttribute (MethodBuilder builder)
1994                 {
1995                         if (ResolveBuilder ())
1996                                 builder.SetCustomAttribute (cab);
1997                 }
1998
1999                 public void EmitAttribute (PropertyBuilder builder)
2000                 {
2001                         if (ResolveBuilder ())
2002                                 builder.SetCustomAttribute (cab);
2003                 }
2004
2005                 public void EmitAttribute (FieldBuilder builder)
2006                 {
2007                         if (ResolveBuilder ())
2008                                 builder.SetCustomAttribute (cab);
2009                 }
2010
2011                 public void EmitAttribute (TypeBuilder builder)
2012                 {
2013                         if (ResolveBuilder ())
2014                                 builder.SetCustomAttribute (cab);
2015                 }
2016
2017                 public void EmitAttribute (AssemblyBuilder builder)
2018                 {
2019                         if (ResolveBuilder ())
2020                                 builder.SetCustomAttribute (cab);
2021                 }
2022
2023                 public void EmitAttribute (ParameterBuilder builder)
2024                 {
2025                         if (ResolveBuilder ())
2026                                 builder.SetCustomAttribute (cab);
2027                 }
2028
2029                 public bool IsDefined {
2030                         get { return type != null && type != NotFound; }
2031                 }
2032
2033                 public void Initialize (CompilerContext ctx, bool canFail)
2034                 {
2035                         this.compiler = ctx;
2036                         Resolve (canFail);
2037                 }
2038
2039                 public bool Resolve (bool canFail)
2040                 {
2041                         if (type != null) {
2042                                 if (IsDefined)
2043                                         return true;
2044                                 if (canFail)
2045                                         return false;
2046                         }
2047
2048                         type = TypeManager.CoreLookupType (compiler, ns, name, Kind.Class, !canFail);
2049                         if (type == null) {
2050                                 type = NotFound;
2051                                 return false;
2052                         }
2053
2054                         return true;
2055                 }
2056
2057                 bool ResolveBuilder ()
2058                 {
2059                         if (cab != null)
2060                                 return true;
2061
2062                         //
2063                         // Handle all parameter-less attributes as optional
2064                         //
2065                         if (!Resolve (true))
2066                                 return false;
2067
2068                         ConstructorInfo ci = TypeManager.GetPredefinedConstructor (type, Location.Null, Type.EmptyTypes);
2069                         if (ci == null)
2070                                 return false;
2071
2072                         cab = new CustomAttributeBuilder (ci, new object[0]);
2073                         return true;
2074                 }
2075
2076                 public bool ResolveConstructor (Location loc, params Type[] argType)
2077                 {
2078                         if (ctor != null)
2079                                 throw new InternalErrorException ("Predefined ctor redefined");
2080
2081                         if (!Resolve (false))
2082                                 return false;
2083
2084                         ctor = TypeManager.GetPredefinedConstructor (type, loc, argType);
2085                         return ctor != null;
2086                 }
2087
2088                 public Type Type {
2089                         get { return type; }
2090                 }
2091         }
2092 }